Comparison of high-resolution echo-planar spectroscopic imaging with conventional MR imaging of prostate tumors in mice
Comparison of high-resolution echo-planar spectroscopic imaging with conventional MR imaging of prostate tumors in mice
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DOI：
10.1002/nbm.954
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发表时间：
2005-08-01
影响因子：
2.9
通讯作者：
Karczmar, GS
中科院分区：
文献类型：
--
作者：
Du, WL;Fan, XB;Karczmar, GS
啮齿动物肿瘤的高光谱和空间分辨率（HiSS）MRI先前已使用常规光谱成像进行，以获得具有改善的对比度和解剖细节的图像。本文所述的工作评估了使用更快的回波平面光谱成像（EPSI）从前列腺癌的啮齿动物肿瘤模型中获取HiSS数据。在4.7 T Bruker扫描仪上实现了高分辨率EPSI脉冲序列。三维EPSI数据沿k空间和时间（自由感应衰减）轴进行沿着傅立叶变换，以产生与每个小图像体素相关的详细水和脂肪光谱。这些数据用于生成光谱参数的图像，例如每个小体素的峰高图像。EPSI有两种变体：梯度回波或自旋回波激发与EPSI读数。在常用的啮齿动物前列腺癌中测试这些成像方法，包括在后腿上植入非转移性AT2.1（n = 3）和转移性AT3.1（n = 4）前列腺肿瘤的7只小鼠，以及原位植入LNCaP前列腺癌的10只小鼠。与梯度回波或自旋回波图像相比，来自EPSI数据集的峰高图像提供了更详细的肿瘤解剖结构，改善了所有回波时间的信噪比和对比度噪声比。结果表明，HiSS MRI数据从小动物模型的前列腺癌可以获得使用EPSI，这种方法提高了成像的异质组织和血管环境内的肿瘤相比，传统的MR技术。版权所有（c）2005年约翰威利父子有限公司。
High spectral and spatial resolution (HiSS) MRI of rodent tumors has previously been performed using conventional spectroscopic imaging to obtain images with improved contrast and anatomic detail. The work described here evaluates the use of much faster echo-planar spectroscopic imaging (EPSI) to acquire HiSS data from rodent tumor models of prostate cancer. A high-resolution EPSI pulse sequence was implemented on a 4.7 T Bruker scanner. Three-dimensional EPSI data were Fourier-transformed along the k-space and temporal (free-induction decay) axes to produce detailed water and fat spectra associated with each small image voxel. The data were used to generate images of spectral parameters, e.g. peak-height images for each small voxel. Two variants of EPSI were performed; gradient-echo or spin-echo excitation with EPSI readout. These imaging methods were tested in commonly used rodent prostate cancers, including seven mice implanted with non-metastatic AT2.1 (n = 3) and metastatic AT3.1 (n = 4) prostate tumors on the hind leg, and 10 mice implanted with LNCaP prostate cancers in situ. The peak-height images derived from EPSI datasets provide more detailed tumor anatomy, improved signal-to-noise and contrast-to-noise ratios compared with the gradient-echo or spin-echo images at all echo times. The results suggest that HiSS MRI data from small animal models of prostate cancer can be acquired using EPSI, and that this approach improves imaging of heterogeneous tissue and vascular environments inside the tumors compared with conventional MR techniques. Copyright (c) 2005 John Wiley & Sons, Ltd.